Respiratory medicine
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Respiratory medicine · May 2001
ReviewAnalysis of montelukast in mild persistent asthmatic patients with near-normal lung function.
Few studies have specifically evaluated controller therapy in patients with mild persistent asthma. We used a subgroup analysis to investigate the effects of montelukast, a potent cysteinyl leukotriene receptor antagonist, on adult patients on the milder end of the asthma severity spectrum. We have identified seven double-blind, randomized, placebo-controlled studies of adult patients with mild-to-moderate chronic asthma in which montelukast was investigated. ⋯ There was a significant improvement in FEV1 in montelukast-treated patients (7-8% over baseline) compared with placebo (1-4% over baseline, between-group difference P < or = 0.02) for all cohorts. Similarly, the percentage of rescue-free days increased substantially more with montelukast (22-30%) than with placebo (8-13%). This subgroup analysis indicates that montelukast produced improvements in parameters of asthma control in patients with milder persistent asthma that should be confirmed in additional prospective trials.
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Respiratory medicine · May 2001
Comparative StudyHow accurate are pulse oximeters in patients with acute exacerbations of chronic obstructive airways disease?
The aim of this study was to determine the extent of correlation and agreement between arterial oxygen saturation and oxygen saturation as recorded by transcutaneous pulse oximetry, with a view to identifying whether pulse oximetry can be used as an alternative to arterial values in the clinical management of patients with acute exacerbations of chronic obstructive airways disease (COAD) in the emergency department. It also aims to determine whether there is a cut-off level of oxygen saturation by pulse oximetry that can screen for significant systemic hypoxia in this group. This prospective study of patients with acute exacerbations of COAD who were deemed by their treating doctor to require an arterial blood gas analysis to determine their ventilatory status, compared arterial oxygen saturation with simultaneously recorded oxygen saturation measured by transcutaneous pulse oximetry. ⋯ With respect to the ROC curve analysis, the 'best' cut-off for detection of hypoxia was at oxygen saturation by pulse oximetry of 92% (sensitivity 100%, specificity 86%). In conclusion, there is not sufficient agreement for oxygen saturation measured by pulse oximetry to replace analysis of an arterial blood gas sample in the clinical evaluation of oxygenation in emergency patients with COAD. However, oxygen saturation by pulse oximetry may be an effective screening test for systemic hypoxia, with the screening cut-off of 92% having sensitivity for the detection of systemic hypoxia of 100% with specificity of 86%.
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Respiratory medicine · May 2001
Is continuous transcutaneous monitoring of PCO2 (TcPCO2) over 8 h reliable in adults?
Monitoring of non-invasive ventilation (NIV) in a non-intensive care unit (non-ICU) setting requires a method of evaluating nocturnal PaCO2, such as transcutaneous CO2 monitoring (TcPCO2). However, changing the probe site after 4 h and recalibrating (as recommended) is time-consuming and impractical. Continuous (8-h) TcPCO2 monitoring at a lower electrode temperature (43 degrees C) in this setting has never been formally studied. ⋯ Over 8 h, no significant drift of the TcPCO2 signal occurred (ANOVA). No discomfort or skin lesion was noted. In conclusion, with an electrode temperature of 43 degrees C, 8-h continuous monitoring of TcPCO2 was well tolerated, without any local side-effects or significant drift of TcPCO2 signal; when compared to previous reports, lowering the electrode temperature did not decrease performance for CO2 monitoring.